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# -R environment
## #R vs RStudio
#### Term:
-Graphical User Interface (GUI)**:** User Interface or a simple term anything that you can see on your computer
-Integrated Development Environment (IDE): A software application to write a computer programm
**Introduction to R:** R is a language and environment for statistical computing and graphics
**The R environment (R-IDE)** has some of features, it includes:
* Input and output , loops function, rekursive
* Create an analytical graph
* Operators in different data object such as matrices, data frame, etc
* Storage facility
* Data handling
* Simple GUI
* Saving graph as pdf
**Introduction to R-Studio:** R-Studio is open-source IDE for R and has better GUI to connect with R
## #RStudio User Interface
RStudio has 4 layer of GUI
## #RStudio support
#### RStudio built in "Help"
* [Getting Started with R](https://support.rstudio.com/hc/en-us/articles/201141096-Getting-Started-with-R)
* [Getting Help with Rstudio](https://support.rstudio.com/hc/en-us/articles/200552336-Getting-Help-with-R)
```r
?mean() # help about function mean()
help(mean) # another help syntax about function mean()
help.start() # go to manuals help (built in help system)
example(mean) # show an example of function mean()
apropos("mean") # show all functions containing at least string "mean()"
```
## #R directories
R directories is the current workspace working directory in our computer- or the address of our folder for save the R objects
```r
getwd() #get the current working director
setwd(mydirectory) #setting the directory, use / in windows
```
#### **Or use the RStudio GUI : Session pane->Set Working Directory->Choose Directory**
## #R packages
Packages are collections of R code. The directory where packages are stored is called the library
#### Available Packages:
* A complete [list of contributed packages](http://cran.r-project.org/web/packages/) is available from [CRAN](https://cran.r-project.org/)
* Search for newest packages, functions, authors, etc from [RDocumentation](https://www.rdocumentation.org/)
#### Setting the library:
```r
library() # to know all packages
installed search() # to see packages currently loaded
.libPaths() # get library path (location)
```
#### Installing additional Packages:
```r
install.packages("nameofpackages") #install
library(nameofpackages) #or #using the packages in RStudio
require(nameofpackages) #same with library()
```
#### Creating Your Own Packages:
* [Writing R Extensions](https://cran.r-project.org/doc/manuals/r-release/R-exts.html) from r-project
* [Creating R Packages: A Tutorial](http://cran.r-project.org/doc/contrib/Leisch-CreatingPackages.pdf) from F Leisch
* [Making R packages Under Windows: A Tutorial](http://www1.appstate.edu/~arnholta/Software/MakingPackagesUnderWindows.pdf) from Rossi's
## #R input/output
#### Input from the current working directory:
```r
# input a file
source("myfile")
```
#### Reusing output results:
The R output can easily be saved and used as input
```r
x<-200 #save x which has value
200y<-x+1000 #x as input for yxy
```
## #R extra environment:
-Build interactive web apps straight from R:
-Build interactive document straight from R:
-The bookdown package is a free and open-source R package built on top of R Markdown to make it really easy to write books and long-form articles/reports.:
*
* For the comprehensive documentation of **bookdown**, please see .
\- R Markdown thesis template using the bookdown package: